mobile/src/App/Pages/Accounts/TwoFactorPage.xaml.cs

using Bit.App.Controls;
using Bit.Core.Abstractions;
using Bit.Core.Utilities;
using System;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace Bit.App.Pages
{
    public partial class TwoFactorPage : BaseContentPage
    {
        private readonly IBroadcasterService _broadcasterService;
        private readonly IMessagingService _messagingService;

        private TwoFactorPageViewModel _vm;

        public TwoFactorPage()
        {
            InitializeComponent();
            SetActivityIndicator();
            _broadcasterService = ServiceContainer.Resolve<IBroadcasterService>("broadcasterService");
            _messagingService = ServiceContainer.Resolve<IMessagingService>("messagingService");
            _vm = BindingContext as TwoFactorPageViewModel;
            _vm.Page = this;
            DuoWebView = _duoWebView;
        }

        public HybridWebView DuoWebView { get; set; }

        public void AddContinueButton()
        {
            if(ToolbarItems.Count == 0)
            {
                ToolbarItems.Add(_continueItem);
            }
        }

        public void RemoveContinueButton()
        {
            if(ToolbarItems.Count > 0)
            {
                ToolbarItems.Remove(_continueItem);
            }
        }

        protected async override void OnAppearing()
        {
            base.OnAppearing();
            _broadcasterService.Subscribe(nameof(TwoFactorPage), async (message) =>
            {
                if(message.Command == "gotYubiKeyOTP")
                {
                    if(_vm.YubikeyMethod)
                    {
                        _vm.Token = (string)message.Data;
                        await _vm.SubmitAsync();
                    }
                }
                else if(message.Command == "resumeYubiKey")
                {
                    if(_vm.YubikeyMethod)
                    {
                        _messagingService.Send("listenYubiKeyOTP", true);
                    }
                }
            });
            await LoadOnAppearedAsync(_scrollView, true, () =>
            {
                _vm.Init();
                return Task.FromResult(0);
            });
        }

        protected override void OnDisappearing()
        {
            base.OnDisappearing();
            if(!_vm.YubikeyMethod)
            {
                _messagingService.Send("listenYubiKeyOTP", false);
                _broadcasterService.Unsubscribe(nameof(TwoFactorPage));
            }
        }

        protected override bool OnBackButtonPressed()
        {
            // ref: https://github.com/bitwarden/mobile/issues/350
            if(_vm.YubikeyMethod)
            {
                if(Device.RuntimePlatform == Device.Android)
                {
                    return true;
                }
                _messagingService.Send("listenYubiKeyOTP", false);
                _broadcasterService.Unsubscribe(nameof(TwoFactorPage));
            }
            return base.OnBackButtonPressed();
        }

        private async void Continue_Clicked(object sender, EventArgs e)
        {
            if(DoOnce())
            {
                await _vm.SubmitAsync();
            }
        }

        private async void Methods_Clicked(object sender, EventArgs e)
        {
            if(DoOnce())
            {
                await _vm.AnotherMethodAsync();
            }
        }

        private async void ResendEmail_Clicked(object sender, EventArgs e)
        {
            if(DoOnce())
            {
                await _vm.SendEmailAsync(true, true);
            }
        }
    }
}